1. Field of the Invention
The present invention relates to a method for checking the transmission properties of a subscriber line circuit together with subscriber line and subscriber terminal equipment connected thereto in a digital time-division multiplex (TDM) telecommunication system, and more particularly in which the subscriber line circuit is composed of a high-voltage module that predominantly contains line drivers as well as elements for indicating subscriber line state and a signal processor module wherein, among other things, the analog-to-digital conversion and the digital-to-analog conversion, the realization of a two-wire-to-four-wire conversion, the setting of the two-wire impedance and the transmission and receiving signal amplification occur.
2. Description of the Prior Art
Heretofore, such tests were implemented with a separate testing device that had access to specific circuit points of the subscriber line circuit or of the subscriber line via operated relays.